EFFECT OF PHYSICAL EXERCISE TRAINING ON MUSCLE STRENGTH AND BODY COMPOSITION, AND THEIR ASSOCIATION WITH FUNCTIONAL CAPACITY AND QUALITY OF LIFE IN PATIENTS WITH ATRIAL FIBRILLATION: A RANDOMIZED CONTROLLED TRIAL

Objective: Atrial fibrillation diminishes cardiac function, exercise tolerance and quality of life. The objective of this study was to determine whether exercise training in atrial fibrillation affects muscle strength, body composition, maximal exercise capacity and walking capacity positively, thus improving quality of life. Design: Randomized clinical trial. Twelve weeks of physical exercise training or control. Patients: Forty-nine patients in permanent atrial fibrillation were randomized to training or control. Methods: Intervention consisted of aerobic training for 1 h 3 times per week at 70% of maximal exercise capacity vs control. Muscle strength, exercise capacity, 6-minute walk test, lean body mass, fat percentage, and quality of life were assessed. Results: Muscle strength increased in the training group (p=0.01), but no change was observed in controls. Lean body mass was unchanged in both groups. Fat percentage decreased in both groups, but there was no significant difference between the groups. Exercise capacity improved in the training group (p<0.001), with no change in the control group. There was a significant difference after the training period between the training and control groups in terms of exercise capacity. (p=0.001). Six-min walk test improved in the training group compared with controls (p<0.01). Overall quality of life score, as measured by the Minnesota Living with Heart Failure Questionnaire, improved in the training group (p=0.03). Quality of life, measured by Short Form-36, improved in the training group in 3 out of 8 subscales: physical functioning (p=0.02), general health perceptions (p=0.001) and vitality p=0.02). Conclusion: Muscle strength, exercise capacity and quality of life increased with exercise training in subjects with atrial fibrillation. Lean body mass was unchanged.